Abstract: Systems and methods consistent with the present invention provide better scheme for updating access control list (ACL) rule entries in a ternary content addressable memory (TCAM). In a firewall, ACL rules are scanned for each packet arriving in a router or switch to determine if a match exists between the packet and any of the patterns. Depending on the pattern matched, the corresponding action may be either to accept or to deny the packet. These rules are stored in a TCAM, and new or updated rules may be added to the TCAM. Systems and methods consistent with the present invention determine whether the new or updated rule has a dependency conflict with existing rules in the TCAM. If not, the rule can be inserted anywhere in the TCAM. Accordingly, the TCAM associated with a firewall's ACL can be updated more quickly and efficiently.

Abstract: A method and system for providing delay bound and prioritized packet dropping are disclosed. The system limits the size of a queue configured to deliver packets in FIFO order by a threshold based on a specified delay bound. Received packets are queued if the threshold is not exceeded. If the threshold is exceeded, a packet having a precedence level less than that of the precedence level of the received packet is dropped. If all packets in the queue have a precedence level greater than that of the packet received, then the received packet is dropped if the threshold is exceeded.

Abstract: A hierarchical multi-rate multi-precedence policer is disclosed. The policer discards packets based on assigned precedence levels. When traffic exceeds an available service rate, the policer drops packets of lower precedence levels to make room for packets of higher precedence levels. In certain implementations, the policer also guarantees bandwidth to each level, thus preventing complete loss of lower precedence traffic when there is a large amount of higher precedence traffic.

Abstract: A multisheathed catheter (12) includes an umbrella (18) positioned on its exterior sheath (16). In use, the umbrella (18) should be positioned within the pulmonary artery. The umbrella (18) has a meshwork (22) through which blood and plasma pass freely therethrough, but which is capable of catching emboli and other foriegn matter before they travel to the lungs. Detection equipment, including a two-dimensional ultrasound probe (44), differential sensors (54 and 56), and chemical sensors (44), are positioned to detect when an embolus has been caught in the umbrella (18). A conduit (64) transports lysing agents (66) such as TPA or heparin to the trapped embolus. In addition, the umbrella (18) can be closed on a trapped embolus using cords (34) and the embolus can be broken apart using ultrasonic probes (70) or can be removed by suction after it is drawn inside the lumen of the catheter (12).